About the plot

The red line is the data for the current year and the blue line (if present) is the data for the previous year. The lines and shading follow a progression from bottom to top as the minimum (thin black line), the 10th percentile (light gray shading), 30th percentile (dark gray shading), median (thick black line), 70th percentile (dark gray shading), 90th percentile (light gray shading), and the maximum (thin black line) over the period shown in the lower left corner.